• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.620-625
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• 2001

The pulpectomy or root canal treatment on primary teeth is to be done when there is evidence of chronic in flammation or necrosis in the radicular pulp. Due to the tortuous and ribbon-shaped anatomy of the primary teeth, the instrumentation of endodontic hand files and barbed broaches is not an easy procedure. Recently, many automatic Ni-Ti rotary instruments have been developed and has made endodontic treatment easier and faster. This report describes two cases of root canal treatment on primary molars using Ni-Ti rotary files. The cervical constricture was eliminated by the crown-down method, as smaller file proceeded unhindered into the apical third of the canal. In addition, the crown-down technique enhanced the efficacy of the endodontic irrigant. The use of rotary instrumentation for primary teeth seemed to be a more effective way to debride the uneven walls of primary teeth.

• Restorative Dentistry and Endodontics
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• v.27 no.3
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• pp.270-276
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• 2002

치근단 수술시 구동형 수술현미경과 미세수술기구들이 사용됨에 따라 치근단 절제술 후 역충전와동의 효과적인 형성 및 충전을 위해 새로운 초음파기구가 개발되었다 따라서 본 연구에서는 최근 상품화되어 사용되고 있는 초음파기구중 신속하게 역충전와동을 형성할 뿐아니라 충분한 깊이를 제공하여 역충전재료의 변연누출 감소에 효과적인 것으로 알려져 있는 3종의 초음파기구를 사용하여 역 충전와동을 형성 한 후 SuperEBA로 충전하여 그 변연누출을 비교하였다. 모두 56개의 근첨형성이 완료된 단근치를 선택하여 Profile .06를 사용하여 근관형성한 후 음성대조군 2개를 제외한 54개의 치아를 수직가압법으로 충전하였다. 근단부 3mm를 절제한 뒤 KaVo Isthmus, KaVo T-shape 그리고 KiS tip을 각각 18개의 치아에 사용하여 역충전와동을 형성하고 그중 각각 2개의 양성대조군 치아를 제외한 나머지 치아에 SuperEBA로 충전하였다. 각치아는 1% methylene blue dye에 침윤시켜 1주일 후 종절단하여 그 색소침투정도를 측정, 비교하였다. 실험결과 측정된 평균 변연누출은 KaVo Isthmus가 $1.5\pm$1.4mm, KaVo T-shape이 1.7$\pm$1.2mm이고 KiS tip은 1.1$\pm$0.7mm 이었으며, 통계적으로 유의할만한 차이는 없었다. 따라서 초음파기구를 사용한 역충전와동의 임상시술 성공여부는 술자의 편의도와 임상적 사용시 조작능력에 달려 있는 것으로 사료된다.

• Restorative Dentistry and Endodontics
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• v.34 no.6
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• pp.484-490
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• 2009

The purpose of this study was to evaluate the effect of soft chelating irrigant on the sealing ability of root fillings by using a glucose leakage test. A total of 45 single-rooted teeth were selected for the study. The teeth were decoronated leaving a total length of 13mm. The root canals prepared using K3 NiTi rotary instruments to an apical dimension of size 45(0.06 taper). The specimens were then randomly divided into 3 experimental groups of 13 roots each and 2 control groups of 3 roots each. Specimen in each group were prepared with different irrigation protocols : group 1, 2.5% NaOCl; group 2, 2.5% NaOCl and 17% EDTA: group 3, 2.5% NaOCl and 15% HEBP. The root canals were filled with gutta-percha and AH Plus sealer using lateral condensation. After 7 days in $37^{\circ}C$, 100% humidity, the coronal-to-apical microleakage was evaluated quantitatively using a glucose leakage model. The leaked glucose concentration was measured with spectrophotometry at 1, 4, 7, 14, 21 and 28 days. There was a tendency of increase in leakage in all experimental groups during experimental period. HEBP-treated dentin showed no significant difference with EDTA-treated dentin during experimental period. From the 21th day onward, HEBP-treated dentin showed significantly lower leakage than smear-covered dentin. HEBP-treated dentin displayed a similar sealing pattern to EDTA-treated dentin and a better sealing ability than smear-covered dentin. Consequently, a soft chelator(HEBP) could be considered as the possible alternative to EDTA.

• The Journal of the Korean dental association
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• v.10 no.1
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• pp.35-40
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• 1972

저자는 임상에서 널리 사용되는 근관충전재료인 산화아연유지놀, N2, MN2 및 Triozinc Paste의 살균효과를 비교하기 위하여 한천배양기 및 혈액가한천배양기상에서 백색포도상구균 및 α-용혈성연질상구균의 두균주를 사용, 실험하여 다음과 같은 결과를 얻었다. 1) 백색포도상구균을 심은 한천배양기상에서 비건조도판을 사용한 실험군에서의 균성장억제대는 MN2, 6. 83; Triozinc paste, 5. 77; N 2, 5. 61; 산화아연유지놀, 3.49mm였다. 2) 백색포도상구균을 심은 한천배양기상에서 건조도판을 사용한 실험군에서의 균성장억제대는 MN2, 4.40; Triozinc paste, 1.46; 산화아연유지놀, 0.99; ㅜ2, 0.84mm였다. 3) 백색포도상구균을 심은 혈액가한천배양기상에서 건조도판을 사용한 실험군에서의 균성장억제대는 MN 2, 1.15; Triozinc paste, 0.55; 산화아연유지놀, 0.54; N2, 0.43mm였다. 4) α-용혈성연질상구균을 심은 용혈가한천배양기상에서 건조도판을 사용한 실험군에서의 균성장억제대는 MN 2, 2.14; Triozinc paste, 1.00; 산화아연유지놀, 0.75; N 2, 0.43mm였다.

• Journal of the korean academy of Pediatric Dentistry
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• v.41 no.2
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• pp.174-179
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• 2014

Dens invaginatus is a developmental anomaly resulting from an infolding of the enamel organ into the dental papilla prior to calcification of the dental tissue. Clinical and radiographic presentation of dens invaginatus shows a lot of variation. The classification proposed by Oehlers(1957) is most commonly used among classifications of dens invaginatus. Several treatments have been suggested to treat Type III dens invaginatus where the pulp remains healthy but the invagination is associated with a periodontitis. The top priority objective is to preserve pulp as sound as possible. Thus, if there is no definite evidence of pulpal disease, the conservative access which treat invagination as distinct from the pulp is necessary. But, Endodontic treatment of Type III dens invaginatus has the particular problems associated with achieving adequate chemomechanical debridement of the root canal system and invagination, predictable length control and consistent filling. In this case report, the endodontic treatment limited within invagination was performed for treatment of Type III dens invaginatus, and filling with Mineral Trioxide Aggregate(MTA) resulted in good prognosis.

• Restorative Dentistry and Endodontics
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• v.32 no.5
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• pp.419-425
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• 2007

The aim of this study was to evaluate the radiopacity and cytotoxicity of three resin-based (AH 26, EZ fill and AD Seal), a zinc oxide-eugenol-based (ZOB Seal), and a calcium hydroxide-based (Sealapex) root canal sealers. Specimens, 10 mm in diameter and 1 mm in thickness, were radiographed simultaneously with an aluminum step wedge using occlusal films, according to ISO 6876/2001 standards. Radiographs were digitized, and the radiopacity of sealers was compared to the different thicknesses of the aluminum step wedge, using the Scion image software. Using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the cytotoxicity of each material was determined in immortalized human periodontal ligament (IPDL) cells. The results demonstrated that EZ fill was the most radiopaque sealer, while Sealapex was the least radiopaque (p < 0.05). AH 26, AD Seal and ZOB Seal presented intermediate radiopacity values. All the materials evaluated, except for Sealapex, presented the minimum radiopacity required by ISO standards. The cell viabilities of resin-based root canal sealers were statistically higher than that of other type of root canal sealers through the all experimental time. Further, EZ fill showed statistically lower cell viability in 24 and 48 hours compared to AD Seal and in 72 hours compared to all other resin-based root canal sealers. However, there was no correlation between the radiopacity and cytotoxicity of three resin-based root canals sealers (p > 0.05). These results indicate that resin-based root canal sealer is more biocompatible and has advantage in terms of radiopacity.

• Restorative Dentistry and Endodontics
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• v.31 no.2
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• pp.119-124
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• 2006

The purpose of this study was to evaluate the effect of newly developed endodontic root canal cleanser (MTAD) on the apical leakage of obturated root canal using an electrochemical method. Canals of 60 extracted single-rooted human teeth were prepared by using a crown-down technique with rotary nickel-titanium files. In Group 1 (positive control group) and 2 (negative centre) group), 5.25% NaOCl was used as a canal irrigant and no canal wall treatment was done. In group 3 only 5.25% NaOCl were used as canal irrigant, canal wall treatment and final rinse. In group 4, specimens were irrigated with 5.25% NaOCl, treated with 5 ml of 17% EDTA for 5 minutes and final rinsed with 5.25% NaOCl Specimens of group 5 were irrigated with 1 3% NaOCl and treated with 5 ml of MTAD for 5 minutes. All root canals are dried with paper points and obtuated with gutta-percha and AH plus as a sealer using a continuous wave of condensation technique except in the group 1. The electrical resistance between the standard and experimental electrodes in canals was measured over a period of 10 days. Rising of apical leakage with time was observed for all the groups. Group 4 and 5 showed lower apical leakage than group 3 but differences between the group 3, 4 and 5 were no statistical significance at any measurement time.

• Restorative Dentistry and Endodontics
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• v.23 no.2
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• pp.561-574
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• 1998

The purposes of this study were to observe the difference in the root canal wall after hand instrumentation or engine-driven Ni-Ti instrumentation under the scanning electron microscope, and to evaluate the apical leakage provided by continuous wave of canal filling technique with or without root canal sealer and smear layer. Twenty recently extracted human maxillary anterior teeth were instrumented with K-type files or engine-driven Ni-Ti files, Quantec series 2000$^{TM}$ and irrigated with 5.25% NaOCl alone or 15% EDT A and final flush of 5.25% NaOCl. After the instrumentation and flushing, teeth were split in half with a knife and a mallet. They were then examined with a scanning electron microscope Forty-four recently extracted human maxillary anterior teeth were divided into four groups with and without smear layer and then warm vertical canal filling using System-B with or without sealer. The extent of leakage was scored after immersion in India ink for 1 week. The results were as follows: 1. No significant difference of smear layer was observed between K-type file-instrumented group and engine-driven Ni-Ti file-instrumented group. 2. A group without smear layer showed significantly less apical leakage than a group with smear layer when sealer was used for the canal filling (p<0.01). 3. There was no significant difference between a group without sealer and smear layer and a group without sealer and with smear layer (p<0.01). 4. In groups without smear layer, a group with sealer showed significantly less apical leakage than a group without sealer (p<0.01). 5. When root canals were irrigated with NaOCl alone, a group with sealer showed significantly less apical leakage than a group without sealer (p<0.01).

• Journal of Veterinary Clinics
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• v.30 no.5
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• pp.380-383
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• 2013

This clinical report describes the dental treatment of canine teeth fractures in three cats. These animals were diagnosed by oral examination and dental radiography as having fractured teeth with pulpal exposure. After endodontic treatment was completed, root canal filling material was removed from the coronal access and a trial post placement was performed. The post was permanently cemented after shortening. Teeth were etched and a bonded composite resin core formed and then shaped using rotary instruments. Fractured canine teeth were treated without any complications observed during a six-month follow-up period, proving that fractured cat canine teeth can be treated successfully with root canal therapy followed by restorative treatment with posts and composite resin.

• Restorative Dentistry and Endodontics
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• v.32 no.1
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• pp.37-46
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• 2007

The C-shaped canal system is an anatomical variation mostly seen in mandibular second molars, although it can also occur in maxillary and other mandibular molars. The main anatomical feature of C-shaped canals is the presence of fins or web connecting the individual root canals. The complexity of C-shaped canals prevents these canals from being cleaned, shaped, and obturated effectively during root canal therapy, and sometimes it leads to an iatrogenic perforation from the extravagant preparation. The purpose of this study was to provide further knowledge of the anatomical configuration and the minimal thickness of dentinal wall according to the level of the root. Thirty extracted mandibular second molars with fused roots and longitudinal grooves on lingual or buccal surface of the root were collected from a native Korean population. The photo images and radiographs from buccal, lingual, apical direction were taken. After access cavity was prepared, teeth were placed in 5.25% sodium hypochlorite solution for 2 hours to dissolve the organic tissue of the root surface and from the root canal system. After bench dried and all the teeth were embedded in a self-curing resin. Each block was sectioned using a microtome (Accutom-50, Struers, Denmark) at interval of 1 mm. The sectioned surface photograph was taken using a digital camera (Coolpix 995, Nikon, Japan) connected to the microscope. 197 images were evaluated for canal configurations and the minimal thickness of dentinal wall between canal and external wall using 'Root Thickness Gauge Program' designed with Visual Basic. The results were as follows : 1. At the orifice level of all teeth, the most frequent observed configuration was Melton's Type C I (73%), however the patterns were changed to type C II and C III when the sections were observed at the apical third. On the other hand, the type C III was observed at the orifice level of only 2 teeth but this type could be seen at apical region of the rest of the teeth. 2. The C-shaped canal showed continuous and semi-colon shape at the orifice level, but at the apical portion of the canal there was high possibility of having 2 or 3 canals 3. Lingual wall was thinner than buccal wall at coronal, middle, apical thirds of root but there was no statistical differences.